WEBVTT - BrainStuff Classics: How Do Migrating Birds Navigate?

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<v Speaker 1>Welcome to brain Stuff, a production of iHeart Radio. Hey

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<v Speaker 1>brain Stuff, Lauren Voke Obam here with another classic episode

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<v Speaker 1>from the podcast archives. This one has to do with

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<v Speaker 1>a bit of animal behavior that's incredibly well observed yet

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<v Speaker 1>not very well understood, bird migration. Hey, I'm Lauren voke Obama.

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<v Speaker 1>This is brain Stuff, and I have a topically relevant

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<v Speaker 1>scenario for your consideration. Let's say you want a change

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<v Speaker 1>of scenery, so you set out with the clothes on

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<v Speaker 1>your back, your innate knowledge of the world, and zip

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<v Speaker 1>all else. Would you be able to travel a few

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<v Speaker 1>thousand miles and wind up somewhere with excellent food options

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<v Speaker 1>and potentially attractive members of your species? And then would

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<v Speaker 1>you be able to get back home a few months later?

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<v Speaker 1>I personally would be hopelessly lost within a week, and yes,

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<v Speaker 1>I would be completely useless during a zombie apocalypse. But

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<v Speaker 1>lots of birds do this every year. Migration can take

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<v Speaker 1>tens of thousands of miles across oceans and continents, and

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<v Speaker 1>often to the exact same summer and winter spots, using

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<v Speaker 1>nearly the exact same roots every time. It's not like

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<v Speaker 1>they have a GPS. Ornithologists have speculated that birds might

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<v Speaker 1>use a number of audio, visual, odorous, and learned social

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<v Speaker 1>cues to get where they're going. But young birds making

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<v Speaker 1>their trip for the very first time have been observed

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<v Speaker 1>to migrate successfully with no chaperones. So, assuming that birds

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<v Speaker 1>aren't feathered cyber drones hacking our global positioning satellites, what

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<v Speaker 1>gives how to birds migrate? Research has revealed that migratory

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<v Speaker 1>birds have vision based magneto reception. They can see magnetic fields,

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<v Speaker 1>and Earth is lousy with magnetic fields. The primary one

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<v Speaker 1>is what makes compasses work. These magnetic fields exist because

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<v Speaker 1>Earth's molten outer core is made up of iron alloys,

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<v Speaker 1>which are switched around by heat coming up off of

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<v Speaker 1>these solid intercore and by the rotation of the Earth.

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<v Speaker 1>That motion and a plus the fact that iron is

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<v Speaker 1>really good at conducting electricity, create a dynamo. A dynamo

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<v Speaker 1>being a generator of electric and magnetic fields, which basically

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<v Speaker 1>makes Earth function like a giant bar magnet. The north

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<v Speaker 1>pole is positive, the south pole is negative, and our

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<v Speaker 1>planet is wrapped in magnetic fields arking between them in

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<v Speaker 1>slopes and curves, and migratory birds can sense those fields.

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<v Speaker 1>Experiments over the past couple of decades have shown that

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<v Speaker 1>birds prepared to migrate south will align themselves with magnetic

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<v Speaker 1>self even in the lab if you create an artificial

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<v Speaker 1>magnetic south. Furthermore, these birds actually see magnetic fields around.

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<v Speaker 1>Researchers fit European robins with either clear or frosted goggles,

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<v Speaker 1>and they found that the birds needed clear vision in

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<v Speaker 1>their right eyes, specifically in order to navigate magnetically. Now

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<v Speaker 1>scientists are studying what biological mechanism might be responsible for this.

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<v Speaker 1>More research needs to be done, but the popular theory

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<v Speaker 1>goes that magnetic fields cause a chemical reaction in birds

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<v Speaker 1>eyes that affect their sensitivity to light, so magnetic fields

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<v Speaker 1>might show up as brighter or darker patterns spread out

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<v Speaker 1>over everything that the bird sees. It's sort of like

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<v Speaker 1>a map on a heads up display. Today's episode is

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<v Speaker 1>based on a video script that I wrote for how

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<v Speaker 1>stuff works dot Com. Brain Stuff is production of I

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<v Speaker 1>Heart Radio in partnership with how stuff works dot Com,

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<v Speaker 1>and it's produced by Tyler Klang and Ramsey Yu. Four

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<v Speaker 1>more podcasts from my heart Radio, visit the heart Radio app,

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